Drug Transcellular Transport Assay Using a High Porosity Honeycomb Film

In vitro transport studies across cells grown on culture inserts are widely used for evaluating pharmacokinetic characteristics such as intestinal membrane permeability. However, measurements of the apparent permeability coefficient of highly lipophilic compounds are often limited by transport across the membrane filters, not by transport across the cultured cells. To overcome this concern, we have investigated the utility of a high-porosity membrane honeycomb film (HCF) for transcellular transport studies. Using the HCF inserts, the apparent permeability coefficient (P_app) of the drugs tested in LLC-PK1 and Caco-2 cells tended to increase with an increase in lipophilicity, reaching a maximum P_app value at Log D higher than 2. In contrast, using the commercially available Track-Etched membrane (TEM) inserts, a maximum value was observed at Log D higher than 1. The basolateral to apical transport permeability P_app(BL→AP) of rhodamine 123 across LLC-PK1 cells that express P-glycoprotein (P-gp) cultured on HCF inserts and TEM inserts was 2.33 and 2.39 times higher than the reverse directional P_app(AP→BL) permeability, respectively. The efflux ratio (P_app(B-A)/P_app(A-B)) of rhodamine 123 in LLC-PK1 expressing P-gp cells using HCF inserts was comparable to that obtained using TEM inserts, whereas the transported amount in both directions was significantly higher when using the HCF inserts. Accordingly, due to the higher permeability and high porosity of HCF membranes, it is expected that transcellular transport of high lipophilic as well as hydrophilic compounds and substrate recognition of transporters can be evaluated more accurately by using HCF inserts.

Establishment of a patient-derived xenograft mouse model of pleomorphic leiomyosarcoma

Soft tissue sarcomas are difficult to treat using chemotherapy owing to a current deficiency in candidate drugs for specific targets. Screening candidate compounds and analyzing therapeutic targets in sarcomas is insufficient, given the lack of an appropriate human sarcoma animal model to accurately evaluate their efficacy, as well as the lack of an adequate technical protocol for efficient transplantation and engraftment of sarcoma specimens in patient-derived xenograft (PDX) models. Accordingly, in this study, we sought to identify the optimal type of sarcoma and develop a protocol for generating a PDX model. We characterized a PDX mouse model using histopathological and immunohistochemical analyses to determine whether it would show pathological characteristics similar to those of human sarcomas. We achieved engraftment of one of the 10 transplanted sarcoma specimens, the xenografted tumor of which exhibited massive proliferation. Histologically, the engrafted sarcoma foci resembled a primary tumor of pleomorphic leiomyosarcoma and maintained their histological structure in all passages. Moreover, immunohistochemical analysis revealed the expression of specific markers of differentiation to smooth muscle, which is consistent with the features of leiomyosarcoma. We thus demonstrated that our pleomorphic leiomyosarcoma PDX mouse model mimics at least one aspect of human sarcomas, and we believe that this model will facilitate the development of novel therapies for sarcomas.

An improved mouse orthotopic bladder cancer model exhibiting progression and treatment response characteristics of human recurrent bladder cancer

Nonmuscle-invasive (superficial) bladder cancer is generally treated via surgical removal, followed by adjuvant therapy (bacillus Calmette-Guerin). However, bladder cancer can often recur, and in a substantial number of recurrent cases, the cancer progresses and metastasizes. Furthermore, residual microtumors following excision may lead to an increased risk of recurrence. An in vivo model mimicking the pattern of urinary bladder microtumor regrowth may provide an effective experimental system for improving postsurgical treatment outcomes. A mouse bladder cancer model established using orthotopic transplant of UM-UC-3 human urinary bladder carcinoma cells has been established, however, to the best of our knowledge, no report has investigated sequential histological changes, including early-phase changes and treatment responses in bladder cancer. In the present study, the efficiency of the model was optimized and the sequential changes were examined using histopathology and in situ imaging. The therapeutic effects of cisplatin (CDDP) and gemcitabine (GEM) were also examined, which are drugs that are often used for follow-up chemotherapy. Tumor-seeding efficiency reached 90-100%, with muscle layer and bladder lumen invasion occurring in ~21 days, using the following modifications: i) Shallow catheter insertion to mitigate bladder wall damage; ii) bladder pretreatment using prewarmed trypsin, followed by light urethral clamping and body temperature maintenance for more efficient removal of transitional epithelium; and iii) seeding with UM-UC-3 cells (rather than HT1376, 5637 or T24 tumor cells) in a medium supplemented with Matrigel. Transplant with UM-UC-3 cells resulted in isolated microlesions that progressed into tumors, invading the bladder lumen and muscle layer to the serosal surface. Tumor growth was markedly reduced by weekly intravenous injections of CDDP and partially suppressed by GEM. Therefore, this model is reliable, and pathological progression and treatment responses recapitulate the features of recurrent human bladder cancer.

Dog-specific hemorrhagic changes induced by liposomal formulations, in the liver and the gallbladder

Although several liposomal drugs, including liposomal doxorubicin, have been approved, the etiology of the pathological responses caused by their physicochemical properties remains unknown. Herein, we investigated the pathological changes in the liver and the gallbladder of dogs following a single injection of liposomal doxorubicin (1 or 2.5 mg/kg) or an empty liposomal formulation (i.e., liposomal formulation without doxorubicin, ca. 21 mg/kg as lipid content). Injection of liposomal doxorubicin or the empty liposomal formulation induced hemorrhagic changes in the liver and the gallbladder. These changes were accompanied by minimal cellular infiltration with no obvious changes in the blood vessels. As there were no differences in the incidence and severity of hemorrhage between the groups administered comparable amounts of total lipid, the physicochemical properties of the liposomal formulation rather than an active pharmacological ingredient, doxorubicin, were associated with the hemorrhagic changes. Furthermore, decreased cytoplasmic granules with low electron density in mast cells beneath the endothelium of the hepatic vein were observed in the liver of dogs treated with liposomal doxorubicin or empty liposomal formulation. Injection of compound 48/80, a histamine releaser induced comparable hemorrhage in dogs, implying that hemorrhage caused by injection of liposomal doxorubicin or the empty liposomal formulation could be attributed to the histamine released from mast cells. The absence of similar hemorrhagic lesions in other species commonly used in toxicology studies (i.e., rats and monkeys), as well as humans, is due to the lack of mast cells beneath the endothelium of the hepatic vein in these species.

FF-10832 enables long survival via effective gemcitabine accumulation in a lethal murine peritoneal dissemination model

Chemotherapy has been the treatment of choice for unresectable peritoneal dissemination; however, it is difficult to eradicate such tumors because of poor drug delivery. To solve this issue, we developed FF‐10832 as liposome‐encapsulated gemcitabine to maintain a high concentration of gemcitabine in peritoneal tumors from the circulation and ascites. A syngeneic mouse model of peritoneal dissemination using murine Colon26 cell line was selected to compare the drug efficacy and pharmacokinetics of FF‐10832 with those of gemcitabine. Despite the single intravenous administration, FF‐10832 treatment enabled long‐term survival of the lethal model mice as compared with those treated with gemcitabine. Pharmacokinetic analysis clarified that FF‐10832 could achieve a more effective gemcitabine delivery to peritoneal tumors owing to better stability in the circulation and ascites. The novel liposome‐encapsulated gemcitabine FF‐10832 may be a curative therapeutic tool for cancer patients with unresectable peritoneal dissemination via the effective delivery of gemcitabine to target tumors.

Reduction Effect of Calcium Alginate on Blood Triglyceride Levels Causing the Inhibition of Hepatic and Total Body Accumulation of Fat in Rats

In this study, rats were fed a high-fat diet containing calcium alginate (Ca-Alg) for 5 weeks to examine the effects of Ca-Alg on lipid metabolism including triglyceride (TG) levels in the blood. We also investigated the mechanism of the TG-reducing effect of Alg in vitro. Rats were randomized into 5 groups: high-fat diet group (14% (w/w) lard, HF); three Ca-Alg-containing diet groups (2.5, 5 or 10% (w/w) Ca-Alg) and a resistant maltodextrin (RMD) diet group as a positive control (with 5% (w/w) RMD). The 10% Ca-Alg group showed a significant reduction of body weight increase from the 7th day. In addition, the increase of TG in blood was significantly suppressed, and the amount of TG excreted in feces was increased. Increase of body fat mass was in the order HF > RMD > Ca-Alg 2.5% > Ca-Alg 5% > Ca-Alg 10%, while the total weight of the extracted fat tissues was significantly reduced in the RMD, 5% and 10% Ca-Alg groups. Hepatic pathology showed clear circular vacuoles apparently representing TG accumulation in the HF group, while fewer vacuoles were seen in the Ca-Alg groups. The results of in vitro experiments indicated that Ca-Alg does not directly inhibit lipase activity, but may suppress absorption of TG by forming non-absorbable macromolecular micelles containing TG. These results suggest that Ca-Alg promotes excretion and suppresses absorption of TG, leading to reduced blood TG levels, and decreased hepatic and total body accumulation of fat. The findings should be helpful for designing future clinical trials.

Intestinal secretion of indoxyl sulfate as a possible compensatory excretion pathway in chronic kidney disease

Indoxyl sulfate (IS) is a protein-bound uremic toxin that progressively accumulates in plasma during chronic kidney disease (CKD), and its accumulation is associated with the progression of CKD. This study examined the intestinal secretion of IS using in situ single-pass intestinal perfusion in a rat model of renal insufficiency, MRP2- and BCRP-overexpressing Sf9 membrane vesicles, and Caco-2 cell monolayers. An in situ single-pass perfusion study in CKD model rats demonstrated that a small amount of IS is secreted into intestinal lumen after iv administration of IS, and the clearance increased AUC-dependently. An excess amount of IS (3 mm) partially inhibited the MRP2- and BCRP-mediated uptake of specific fluorescent substrates, CDCF and Lucifer yellow, respectively, into the membrane vesicles, although IS was not taken up at a physiological concentration, 10 μm. In the Caco-2 cell monolayers, the IS transport was higher in the absorptive direction than in the secretory direction (p < 0.05). p-Aminohippuric acid (PAH) strongly inhibited IS transport in both directions (absorptive, p = 0.142; secretory, p < 0.01). Given that the blood IS levels are much higher than those in the intestinal lumen, it is possible that this unknown PAH-sensitive system contributes to the intestinal IS secretion. Although in situ inhibition study is needed to confirm that this unknown transporter mediates the in vivo intestinal secretion of IS, we speculate that this unknown active efflux system works as a compensatory excretion pathway for excess organic anions such as IS especially in end-stage renal disease.

Dedifferentiated retroperitoneal liposarcoma spontaneously occurring in an aged SD rat

Liposarcoma is a rare neoplasm in rats and is characterized by the presence of lipoblasts containing multiple cytoplasmic vacuoles. We encountered a rare type of liposarcoma in a male SD (Crj:CD(SD)IGS) rat during a long-term study to gather background data. At necropsy at 105 weeks of age, there was a large amount of fatty tissue covering the mesentery, pancreas, and retroperitoneum; a white nodule in the right kidney; and paleness of the liver. Microscopically, the tumor had a well-differentiated component and dedifferentiated high-grade component. Immunohistochemical and electron microscopic examinations revealed that the pleomorphic tumor cells retained the characteristics of lipoblasts. Distant or disseminated metastasis was also confirmed in various organs. A liposarcoma with these histological features is extremely rare in rats, and this is the first report of a highly metastatic dedifferentiated type of liposarcoma originating from the abdominal fat tissue in a rat.

FF-10502, an Antimetabolite with Novel Activity on Dormant Cells, Is Superior to Gemcitabine for Targeting Pancreatic Cancer Cells

In this paper, we report that 1-(2-deoxy-2-fluoro-4-thio-β-d-arabinofuranosyl) cytosine (FF-10502), a pyrimidine nucleoside antimetabolite with a chemical structure similar to gemcitabine, shows beneficial anticancer activity via a novel mechanism of action on dormant cells. The growth inhibition of pancreatic cancer cell lines by FF-10502 (IC₅₀, 60-330 nM) was moderately weaker than that by gemcitabine in vitro. In contrast, an in vivo orthotopic implantation model in mice with established human pancreatic cancer cell line, SUIT-2, revealed no mortality with FF-10502 intravenous treatment, which was related to regression of implanted tumor and little metastasis, whereas 75% of the mice treated with gemcitabine died by day 128. Two in vivo patient-derived xenograft models with gemcitabine-resistant pancreatic cancer cells also demonstrated complete tumor growth suppression with FF-10502, but only partial inhibition with gemcitabine. We also investigated the mechanism of action of FF-10502 by using dormant cancer cells, which are reportedly involved in the development of resistance to chemotherapy. In vitro serum starvation-induced dormant SUIT-2 cells developed resistance to gemcitabine even in combination with DNA damage inducers (DDIs; H₂O₂, cisplatin, and temozolomide). Interestingly, FF-10502 in combination with DDIs significantly induced concentration-dependent cell death in accordance with enhanced DNA damage. FF-10502 was far more potent than gemcitabine in inhibiting DNA polymerase β, which may explain the difference in dormant cell injury, although further investigations for direct evidences are necessary. In conclusion, our study demonstrated the beneficial antitumor effects of FF-10502 in clinically relevant in vivo models, and suggests the importance of preventing DNA repair unlike gemcitabine.

Abstract B112: Development and preclinical evaluation of a novel BET inhibitor FF-1027T

Bromodomain and extra-terminal (BET) family of proteins regulate gene expression by binding acetylated-lysine residue in histone at the gene promoter and enhancer elements through the two bromodomains (BD1 and BD2). Subsequently, they activate transcriptional elongation at the binding sites. Small-molecule compounds inhibiting the interaction between BET proteins and acetylate-lysine in histone have been expected as a promising strategy for cancer therapy. They can show pharmacologic action by regulating the transcription of MYC and other cancer-associated genes. We identified a novel BET inhibitor, FF-1027T, that is structurally different from the (+)JQ-1 class BET inhibitors such as OTX015. FF-1027T is more soluble in aqueous solution than known BET inhibitors, which offers an advantage in the application of drug formulations. Through the TR-FRET assay, FF-1027T exhibited binding to BRD2/3/4 with a preference for BD1 over BD2. FF-1027T showed antiproliferative activity in vitro across broad cancer cell lines derived from hematologic malignancies or solid tumors. In accordance with the previous report about BET inhibitors, FF-1027T displayed higher antiproliferative activity to hematologic malignancies than solid tumor-derived cell lines with less than 100 nM GI50 values (12 out of 21 cells lines). In particular, FF-1027T showed anti-proliferative activities against cell lines derived from solid tumors, such as colon, lung, breast, and prostate cancer, with less than 300 nM GI50 values in almost 30% of the cell lines. In AML xenograft tumor models, oral or intravenous administration of FF-1027T resulted in almost complete reduction of tumor growth. Intravenous treatment was achieved by high solubility in an aqueous solution of FF-1027T. Our present results suggested that gastrointestinal tract (GI) damage through topical effects of BET inhibitors on the mucosal surface can be avoided by intravenous administration. These results demonstrated that FF-1027T is a potent BET inhibitor and supports the clinical further development of FF-1027T in hematologic malignancies and solid tumors.

Citation Format: Keiko Makita, Kazunori Saeki, Tadashi Tanaka, Yasutomo Kawanishi, Toshifumi Kimura, Shinichi Watanabe, Chihaya Kakinuma, Shinji Hagiwara, Yasuhiro Shimada. Development and preclinical evaluation of a novel BET inhibitor FF-1027T [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B112.

Investigation into metastatic processes and the therapeutic effects of gemcitabine on human pancreatic cancer using an orthotopic SUIT-2 pancreatic cancer mouse model

Prognosis of pancreatic cancer is poor, thus the development of novel therapeutic drugs is necessary. During preclinical studies, appropriate models are essential for evaluating drug efficacy. The present study sought to determine the ideal pancreatic cancer mouse model for reliable preclinical testing. Such a model could accurately reflect human pancreatic cancer phenotypes and predict future clinical trial results. Systemic pathology analysis was performed in an orthotopic transplantation model to prepare model mice for use in preclinical studies, mimicking the progress of human pancreatic cancer. The location and the timing of inoculated cancer cell metastases, pathogenesis and cause of fatality were analyzed. Furthermore, the efficacy of gemcitabine, a key pancreatic cancer drug, was evaluated in this model where liver metastasis and peritoneal dissemination occur. Results indicated that the SUIT-2 orthotopic pancreatic cancer model was similar to the phenotypic sequential progression of human pancreatic cancer, with extra-pancreatic invasion, intra-peritoneal dissemination and other hematogenous organ metastases. Notably, survival was prolonged by administering gemcitabine to mice with metastasized pancreatic cancer. Furthermore, the detailed effects of gemcitabine on the primary tumor and metastatic tumor lesions were pathologically evaluated in mice. The present study indicated the model accurately depicted pancreatic cancer development and metastasis. Furthermore, the detailed effects of pancreatic cancer drugs on the primary tumor and on metastatic tumor lesions. We present this model as a potential new standard for new drug development in pancreatic cancer.

Abstract 5127: In vitro and in vivo evaluation of FF-10502-01, a new pyrimidine nucleoside analogue

Introduction:FF-10502-01 is a synthetic pyrimidine nucleoside analogue structurally similar to gemcitabine (gem) with a substitution of sulfur for oxygen in the pentose ring. The anti-tumor effects of FF-10502-01 were studied in solid tumor cell lines and human tumor xenograft models.

Methods:10 human solid tumor cell lines were studied and included the following: 4 pancreatic (PANC) (BxPC-3, SUIT-2, Capan-1 and MIA PaCa-2), colon (HCT116), lung (NCI-H460), ovary (SK-OV-3), prostate (LNCap.FGC), breast (MDA-MB231) and mantle cell lymphoma (MCL) (Jeko-1). The effect of FF-10502-01 on DNA synthesis versus gem was evaluated in a PANC cell line (Capan-1). Tumor growth suppression was evaluated in human PANC xenograft models, SUIT-2 and Capan-1. FF-10502-01 or gem was administered at 240 or 480 mg/kg once a week starting 7d after orthotopic transplantation for 18 weeks, n=20/grp. Animals were followed for 128d after transplantation. Capan-1 was transplanted SC into nude mice (n=8/grp). FF-10502-01 or gem was administered at 120, 240, 360 or 480 mg/kg once weekly x 4 weeks 7d after transplantation. Tumor growth inhibitory effects were evaluated for 27d after starting treatment. FF-10502-01 single-dose pharmacokinetics (PK) were investigated in the mouse, rat and dog.

Results:FF-10502-01 demonstrated in vitro activity against the PANC, colon, lung, ovarian, prostate and MCL cell lines, with IC50s of 30 – 330 nM. The activity was 1.5 – 15-fold lower than gem, however, FF-10502-01 demonstrated a 23-fold higher inhibition of DNA α-polymerase-mediated synthesis over gem. In the SUIT-2 orthotropic implant model, both gem and FF-10502-01 improved survival over vehicle controls. Med survival was not reached for the 480 mg/kg gem grp or either the 240 or 480 mg/kg FF-10502-01 grps. The survival rate was 5%, 25%, 75% for the vehicle, 240 and 480 mg/kg gem grps (p&lt;0.0001 versus vehicle), and 100% for the 240 and 480 mg/kg FF-10502-01 grps (p&lt;0.0001 versus gem grps), respectively. In the Capan-1 xenograft model, both FF-10502-01 and gem demonstrated statistically significant tumor growth suppression versus vehicle control; FF-10502-01 demonstrated equivalent tumor growth suppression with less effect on body weight than gem at clinically achievable doses.

PK following single bolus IV doses indicated a similar PK profile to other pyrimidine nucleoside analogues, including gem.

Conclusions:FF-10502-01 is a new pyrimidine nucleoside analogue with demonstrated preclinical efficacy against solid tumors and a potentially more tolerable safety profile than gem.

Citation Format: Shinji Mima, Hiroki Nishikawa, Shinichi Watanabe, Tamami Higuchi, Takeaki Suzuki, Hiroyuki Iwamura, Chihaya Kakinuma, Takaaki Nakamura, Yasuhiro Shimada. In vitro and in vivo evaluation of FF-10502-01, a new pyrimidine nucleoside analogue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5127. doi:10.1158/1538-7445.AM2017-5127

Abstract 5112: Evaluation of FF-10502-01, a new pyrimidine nucleoside analogue, in pancreatic (PANC) patient-derived xenograft (PDX) models compared to gemcitabine and in combination with nab-paclitaxel

Introduction

FF-10502-01 is a synthetic pyrimidine nucleoside analogue structurally similar to gem with a substitution of sulfur for oxygen in the pentose sugar. In previous studies, FF-10502-01 demonstrated preclinical efficacy across multiple solid tumors, including PANC cancer. In this study, we investigated the anti-tumor effect of FF-10502-01 in PANC PDX models.

Methods

10 PANC PDX tumors were sourced from primary (2) or metastatic sites (8). 7 demonstrated high resistance (HR) to gem, 1 intermediate, and 2 low. In the dose-finding study, 3 PDX models were studied in 9 grps of NOD-SCID mice (n=10/grp), treated with 240 or 480 mg/kg FF-10502-01, 3 or 6 mg/kg nab-pac or 240 mg/kg gem, alone and in combination for 28d, followed by 28d observation. The definitive study consisted of 7 PDX models. 6 grps (n=10/grp) were treated with 240 or 480 mg/kg FF-10502-01, 6 mg/kg nab-pac or 240 mg/kg gem, alone and/or in combination for 28d, followed by 28d observation. After subcutaneous transplantation, animals were left undisturbed for 7d. Animals were monitored weekly and tumor volume measured with calipers. Average tumor volume (mm3) for each group at randomization into treatment grps ranged from 184.34 – 199.51 (SD ± 20.94 – 30.40). Statistical significance was determined using one-way ANOVA and Tukey’s test.

Results

At clinically relevant doses, FF-10502-01, alone and in combination with nab-pac demonstrated greater tumor growth suppression than vehicle-treated animals (p≤0.0001). In 7 models, FF-10502-01/nab-pac demonstrated higher tumor growth suppression than gem/nab-pac (p≤0.5, p≤0.01 or p≤0.001), irrespective of resistance to gem. In 3 models, there was no difference, but these models were highly responsive to gem/nab-pac, thus minimizing the effects of FF-10502-01/nab-pac. Despite statistical insignificance, FF-10502-01/nab-pac still demonstrated greater tumor growth inhibitory activity to gem/nab-pac. In HR gem models, FF-10502-01 was superior to gem (p≤0.0001, p≤0.001, p≤0.05) in 3 of 7, and FF-10502-01/nab-pac was superior to gem/nab-pac in 6 of 7 (p nab-pac (p≤0.0001, p≤0.0001, p≤0.01, p≤0.05). FF-10502-01/nab-pac also was more tolerable than gemcitabine/nab-pac, as demonstrated by less weight loss.

Conclusions

FF-10502-01 is a new pyrimidine nucleoside analogue with demonstrated preclinical efficacy in solid tumors, including PANC cancer. In PANC PDX models, FF-10502-01 alone and in combination with nab-pac demonstrated higher efficacy and better tolerability than gem alone or gem/nab-pac. FF-10502-01 is in Phase 1 clinical development.

Citation Format: Takeaki Suzuki, Linda J. Paradiso, Jill Ricono, Jonathan Nakashima, Yoshihide Iwaki, Shinji Mima, Takayuki Yamada, Chihaya Kakinuma, Hiroyuki Iwamura, Shinichi Watanabe. Evaluation of FF-10502-01, a new pyrimidine nucleoside analogue, in pancreatic (PANC) patient-derived xenograft (PDX) models compared to gemcitabine and in combination with nab-paclitaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5112. doi:10.1158/1538-7445.AM2017-5112

Developmental changes of brain distribution and localization of oseltamivir and its active metabolite Ro 64-0802 in rats

Oseltamivir, a prodrug of the neuraminidase inhibitor [3R, 4R, 5S]-4-Acetamide-5-amino-3-(1-ethylpropyl)-1-cyclohexene-1-carboxylate phosphate (Ro 64-0802), is widely used for treatment of influenza infections in Japan, but may be associated with mental instability and suicidal tendencies as a rare side effect, especially in infants and young patients. We examined developmental changes in the brain distribution of oseltamivir and Ro 64-0802, and in the expression of P-glycoprotein (P-gp) at the blood-brain barrier (BBB) in rats by 8 weeks. Brain concentration and Kp(,app,brain) (brain-to-plasma concentration ratio) of oseltamivir were highest in 2-week-old rats (1.45 µg/g brain and 0.14, respectively), and were negatively correlated with both age and P-gp expression at the BBB. In contrast, brain concentration and Kp(,app,brain) of Ro 64-0802 after oral gavage of oseltamivir were lowest in 2-week-old rats (0.02 µg/g brain and 0.02), and increased with age. Mass imaging analysis revealed that both compounds were distributed homogenously in brain cross-sections, including the hippocampus. From these results, it was estimated that oseltamivir concentration throughout the brain cross-sections was 70-fold and 0.9-fold higher than that of Ro 64-0802 in 2-week-old and 8-week-old rats, respectively. Such developmental changes of prodrug/drug concentration ratio, if they also occur in humans, may provide a rational basis for the putative central nervous system (CNS) side effects in young patients.

Alginate enhances excretion and reduces absorption of strontium and cesium in rats

Alginate (ALA), which is an intercellular polysaccharide associated with brown algae, is used as a food additive, a health food and a medicine. Here, we first examined the adsorption of strontium (Sr) and cesium (Cs) by ALA in vitro, and then evaluated the effects of ALA on absorption and excretion of Sr and Cs in rats, in order to evaluate its potential usefulness for minimizing radiation damage from materials released after a nuclear accident. Both Sr and Cs were concentration-dependently adsorbed by sodium alginate (ALA-Na) in vitro. In rats given diet containing either ALA-Na or calcium alginate (ALA-Ca) for two weeks, the plasma concentration of Sr gradually decreased compared with the controls (normal diet); however, in the case of Cs, the plasma concentration was decreased only in the ALA-Ca group, but not the ALA-Na group. Moreover, we examined the effect of preadministration of diet containing either ALA-Na or ALA-Ca on absorption of Sr and Cs administered orally as the chloride salts to rats. Absorption of both Sr and Cs was reduced in the ALA-Ca group, while absorption of only Sr was reduced in the ALA-Na group. Safety assessments indicated that ALA-Ca is safer than ALA-Na. These results indicate that ALA-Ca reduces absorption and promotes excretion of both Sr and Cs, while ALA-Na does so only for Sr.

Biochemical investigation and gene expression analysis of the immunostimulatory functions of an edible Salacia extract in rat small intestine

Roots and bark from plants belonging to genus Salacia of the family Hippocrateaceae (Salacia reticulata, Salacia oblonga, etc.) have been used for traditional Ayurvedic medicine, particularly for the treatment of diabetes. In our study, we evaluated the gene expression profiles in the small intestinal epithelium of rats that were given a Salacia plant extract to gain insight into its effects on the small intestine. In detail, DNA microarray analysis was performed to evaluate the gene expression profiles in the rat ileal epithelium. The intestinal bacterial flora was also studied using T-RFLP (Nagashima method) in these rats. Expressions of many immune-related genes, especially Th1-related genes associated with cell-mediated immunity, were found to increase in the small intestinal epithelium and the intestinal bacterial flora became similar to those in the case with Salacia plant extract administration. Our study thus revealed that Salacia plant extract exerts bioregulatory functions by boosting intestinal immunity.

Evaluation of the inhibitory effect of dihydropyridines on N-type calcium channel by virtual three-dimensional pharmacophore modeling

Currently, a new type of calcium channel blockers, which can inhibit not only L-type calcium channels abundantly expressed in vascular smooth muscles, but also N-type calcium channels that abound in the sympathetic nerve endings, have been developed. In this study, analysis on a like-for-like basis of the L- and N-type calcium channel-inhibitory activity of typical dihydropyridine-type calcium-channel blockers (DHPs) was performed. Moreover, to understand the differences of N-type calcium channel inhibition among DHPs, the binding of DHPs to the channel was investigated by means of hypothetical three-dimensional pharmacophore modeling using multiple calculated low-energy conformers of the DHPs. All of the tested compounds, i.e. cilnidipine (CAS 132203-70-4), efonidipine (CAS 111011-76-8), amlodipine (CAS 111470-99-6), benidipine (CAS 85387-35-5), azelnidipine (CAS 123524-52-7) and nifedipine (CAS 21829-25-4), potently inhibited the L-type calcium channel, whereas only cilnidipine inhibited the N-type calcium channel (IC50 value: 51.2 nM). A virtual three-dimensional structure of the N-type calcium channel was generated by using the structure of the peptide omega-conotoxin GVIA, a standard inhibitor of the channel, and cilnidipine was found to fit well into this pharmacophore model. Lipophilic potential maps of omega-conotoxin GVIA and cilnidipine supported this finding. Conformational overlay of cilnidipine and the other DHPs indicated that amlodipine and nifedipine were not compatible with the pharmacophore model because they did not contain an aromatic ring that was functionally equivalent to Tyr13 of omega-conotoxin GVIA. Azelnidipine, benidipine, and efonidipine, which have this type of aromatic ring, were not positively identified due to intrusions into the excluded volume. Estimation of virtual three-dimensional structures of proteins, such as ion channels, by using standard substrates and/or inhibitors may be a useful method to explore the mechanisms of pharmacological and toxicological effects of substrates and/or inhibitors, and to discover new drugs.

Oseltamivir (Tamiflu) efflux transport at the blood-brain barrier via P-glycoprotein

Oseltamivir (Tamiflu, Roche, Nutley, NJ), an ester-type prodrug of the anti-influenza drug Ro 64-0802 (oseltamivir carboxylate), has been reported to be associated with neuropsychiatric side effects, which are likely to be caused by distribution of oseltamivir and/or its metabolite into the central nervous system. Enhanced toxicity and brain distribution of oseltamivir in unweaned rats led us to hypothesize that the low level of distribution of oseltamivir and/or Ro 64-0802 in adult brain was caused by the presence of a specific efflux transporter at the blood-brain barrier. We examined the possible role of P-glycoprotein (P-gp) as the determinant of brain distribution of oseltamivir and Ro 64-0802 both in vitro using LLC-GA5-COL150 cells, which overexpress human multidrug resistance protein 1 P-gp on the apical membrane, and in vivo using mdr1a/1b knockout mice. The permeability of oseltamivir in the basal-to-apical direction was significantly greater than that in the opposite direction. The directional transport disappeared on addition of cyclosporin A, a P-gp inhibitor. The brain distribution of oseltamivir was increased in mdr1a/1b knockout mice compared with wild-type mice. In contrast, negligible transport of Ro 64-0802 by P-gp was observed in both in vitro and in vivo studies. These results show that oseltamivir, but not Ro 64-0802, is a substrate of P-gp. Accordingly, low levels of P-gp activity or drug-drug interactions at P-gp may lead to enhanced brain accumulation of oseltamivir, and this may in turn account for the central nervous system effects of oseltamivir observed in some patients.

Role of fibrosis-related genes and pancreatic duct obstruction in rat pancreatitis models: implications for chronic pancreatitis

Human chronic pancreatitis is characterized by irreversible fibrosis, whereas pancreatic fibrosis in animal models is reversible. In this study, we compare the development of pancreatic fibrosis in the dibutyltin dichloride (DBTC) model, WBN/Kob rats and bile duct-ligated (BDL) rats. DBTC (8 mg/kg) was administered to LEW rats, and the pancreas was histopathologically investigated sequentially. Male and female WBN/Kob rats aged 4, 6 and 8 months were also examined. BDL rats were prepared by ligation of the bile duct at the duodenal portion and sacrificed at 3 or 7 days after ligation. Fibrosis in the DBTC model peaked after 1 week and was limited to the areas around the pancreatic ducts after 2 weeks, and was composed of both type I and type III collagen. In contrast, fibrosis in male WBN/Kob rats peaked at age 4 months, expanded into intralobular area, and was composed of type III collagen. It exhibited almost no type I collagen and a marked tendency to regress. Pancreatic fibrosis in BDL rats was somewhat difficult to induce and required increased stimulation. This suggests that fibrosis in human biliary pancreatitis may gradually form based on weak, continuous stimulation. We conclude that type I collagen may be involved in the progression of irreversible fibrosis. The imbalance between synthesis and degradation of extracellular matrix molecules or degree of stimulation over a certain period may lead to pancreatic fibrosis. Gene expressions of prolyl hydroxylase and tissue inhibitors of matrix metalloproteinase-2 were elevated.

Improving effect of ethyl eicosapentanoate on statin-induced rhabdomyolysis in Eisai hyperbilirubinemic rats

The effect of ethyl eicosapentanoate (EPA-E) on statin-induced rhabdomyolysis was investigated by co-administration of EPA-E and pravastatin (PV), as a typical statin, to Eisai hyperbilirubinemic rats (EHBR). It was confirmed that the plasma PV concentration was not affected by simultaneous administration of EPA-E, and there was no cumulative increase of PV during prolonged co-administration of EPA-E and PV. Muscular degeneration was prominent (incidence 5/5; average grade 3.5 (range 2-4)) in EHBR treated with PV alone at 200 mg/kg/day for 14 days, but co-administration of EPA-E at doses of 100, 300, and 1000 mg/kg/day decreased the average grades to 1.4 (range 0.3-3.0), 0.5 (0.2-1.0), and 0.6 (0.0-1.7), respectively. Creatine phosphokinase (CPK) and myoglobin levels in plasma were well correlated with the grade of skeletal muscle degeneration. Thus, EPA-E appears to reduce the severity of statin-induced rhabdomyolysis.

Establishment of an In Vitro High-Throughput Screening Assay for Detecting Phospholipidosis-Inducing Potential

Excessive accumulation of phospholipids results in phospholipidosis (PL), which may interfere with cellular functions, leading to acute or chronic disease or even death. Electron-microscopic detection of cytoplasmic lamellar bodies is often used as a diagnostic criterion of PL, but a faster, more convenient procedure is required for high-throughput assay of the PL-inducing potential of candidate drugs. We have developed a 96-well microplate cell-culture method for detecting PL, using a phosphatidylcholine-conjugated dye (NBD-PC) and a fluoro-microplate reader. The fluorescence intensity due to NBD-PC was normalized to that of Hoechst33342, used as an indicator of cell number, to obtain the amount of NBD-PC taken up per living cell. To select a suitable cell type, we examined the PL-detection sensitivity of five cell lines, as well as human and rat primary hepatocyte cultures, with five cationic amphiphilic drugs (CAD) as PL inducers and a negative control compound. The cell lines CHO-K1 and CHL/IU gave the best results. The NBD-PC uptake per CHO-K1 cell showed a high correlation with the pathological score of PL for 24 compounds, including PL-positive and negative compounds. This high-throughput screening assay for PL-inducing potential (HTS-PL assay) offers high sensitivity and accuracy, and it allows simultaneous determination of cytotoxicity.

Increased Very Low Density Lipoprotein Secretion and Gonadal Fat Mass in Mice Overexpressing Liver DGAT1

Acyl-CoA:diacylglycerol acyltransferases (DGATs) catalyze the last step in triglyceride (TG) synthesis. The genes for two DGAT enzymes, DGAT1 and DGAT2, have been identified. To examine the roles of liver DGAT1 and DGAT2 in TG synthesis and very low density lipoprotein (VLDL) secretion, liver DGAT1- and DGAT2-overexpressing mice were created by adenovirus-mediated gene transfection. DGAT1-overexpressing mice had markedly increased DGAT activity in the presence of the permeabilizing agent alamethicin. This suggests that DGAT1 possesses latent DGAT activity on the lumen of the endoplasmic reticulum. DGAT1-overexpressing mice showed increased VLDL secretion, resulting in increased gonadal (epididymal or parametrial) fat mass but not subcutaneous fat mass. The VLDL-mediated increase in gonadal fat mass might be due to the 4-fold greater expression of the VLDL receptor protein in gonadal fat than in subcutaneous fat. DGAT2-overexpressing mice had increased liver TG content, but VLDL secretion was not affected. These results indicate that DGAT1 but not DGAT2 has a role in VLDL synthesis and that increased plasma VLDL concentrations may promote obesity, whereas increased DGAT2 activity has a role in steatosis.

Eisai hyperbilirubinemic rat (EHBR) as an animal model affording high drug-exposure in toxicity studies on organic anions

The Eisai hyperbilirubinemic rat (EHBR) should be a useful animal model for studies on the toxicity of organic anions which are substrates of multidrug resistance-associated protein 2 (Mrp2), since the systemic exposure to these compounds is expected to be increased in EHBR. In this study, we tested the value of EHBR for this purpose, using pravastatin (PV) and methotrexate (MTX) as model compounds. In the case of a single oral dose of PV (200 mg/kg), C(max) in plasma was 4.0-fold higher and AUC(0-infinity) was 3.6-fold larger than those of normal Sprague-Dawley rats (SDR), respectively. When multiple doses of PV were given to EHBR without co-administration of any other compound, drug-induced skeletal muscle toxicity (myopathy/rhabdomyolysis) and increased creatine phosphokinase (CPK) level were observed, whereas a control experiment using SDR did not show any toxic change. When a single dose of MTX (0.6 mg/kg) was given to EHBR orally, C(max) was 1.7-fold higher and AUC(0-infinity) was 1.6-fold larger than those of SDR, respectively. When multiple doses of MTX were given to EHBR, the changes in bone marrow, spleen and intestines were more severe than those in SDR. These findings support the view that EHBR would be a valuable animal model for toxicity studies on organic anion compounds which are substrates of Mrp2.

Histopathologic difference between chronic pancreatitis animal models and human chronic pancreatitis

OBJECTIVES

There are many experimental models for chronic pancreatitis. However, it remains unclear which animal models of pancreatic fibrosis can be categorized as chronic pancreatitis models. We compared the histologic features of some animal models of pancreatic fibrosis/chronic pancreatitis and chronic pancreatitis in humans.

METHODS AND RESULTS

Human chronic pancreatitis due to chronic alcohol abuse and unknown etiology showed interlobular fibrosis and a cirrhosis-like appearance. Histopathologically, spontaneous pancreatitis models, WBN/Kob rats and OLETF rats, showed localized/nodular fibrotic lesions, which consisted of swollen, aggregated, atrophic islets of Langerhans; loss of the exocrine parenchyma and hemosiderin deposition that was seldom distributed in the interlobular area. On the other hand, fibrosis in the canine model, which was produced by combining alcohol administration with incomplete pancreatic duct obstruction, was characterized by interlobular fibrosis admixed with a cirrhosis-like appearance very similar to that in human chronic pancreatitis.

CONCLUSION

Most experimental models for chronic pancreatitis, except alcohol administration combined with other procedures such as incomplete pancreatic duct obstruction, are different from human chronic pancreatitis.

The gene expression of hepatic proteins responsible for DNA repair and cell proliferation in tamoxifen-induced hepatocarcinogenesis

Altered gene expression of the DNA repair- and cell proliferation-associated proteins/enzymes was examined during the process of tamoxifen-induced hepatocarcinogenesis in female Sprague-Dawley rats. When rats were treated by gavage with a single dose of tamoxifen (20 mg/kg body weight) or with the same dose given at 24-h intervals for 2, 12 or 52 weeks, no histopathological change was observed in the liver after 2 weeks. Pathologically altered cell foci and placental form of glutathione-S-transferase (GST-P)-positive foci were observed in the liver after 12 weeks of treatment. Treatment for 52 weeks resulted in the formation of liver hyperplastic nodules that strongly expressed GST-P. During the process of carcinogenesis, changes in hepatic gene expression of DNA repair proteins/enzymes (XPA and XPC, xeroderma pigmentosum complementation groups A and C, respectively; APE, apurinic/apyrimidinic endonuclease) and of cell proliferation-associated proteins (c-myc; PCNA, proliferating cell nuclear antigen; cyclin D1, cyclin B, and p34cdc2) were examined by RT-PCR. The gene expression of XPA and APE was increased by the tamoxifen treatment for 2 or 12 weeks, but no increase was observed after the 52-week treatment. In addition, no significant change in XPC gene expression occurred at any period examined. The gene expression of c-myc, PCNA, and cyclin D1 was increased in a time-dependent fashion up to 12 weeks of treatment, and this increase was maintained up to 52 weeks of treatment. The gene expression of cyclin B and p34cdc2 was increased after the 1-day treatment, reverted to the control level at 2 and 12 weeks of treatment, and was remarkably increased after the 52-week treatment. In the present study, we demonstrate the altered gene expression of various proteins/enzymes involved in DNA repair, cell growth and the cell cycle during the process of tamoxifen-induced hepatocarcinogenesis. We discuss the relationship between the altered gene expression and hepatocarcinogenesis.

Impaired fertility in female mice lacking urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI) is a serine proteinase inhibitor that is found in blood and urine. To investigate the physiological functions of UTI in vivo, we generated UTI-deficient mice by gene targeting. The mice showed no obvious abnormalities and appeared healthy. However, the females displayed a severe reduction in fertility. Wild-type embryos developed normally when transplanted into UTI-deficient female mice, suggesting that UTI-deficient females have a normal ability to maintain pregnancy. The number of naturally ovulated oocytes from UTI-deficient mice was greatly reduced compared with that from wild-type mice. Histologically, oocytes with disorganized corona radiata were frequently seen in the ovaries of UTI-deficient mice after hormonal stimulation. When ovaries from UTI-deficient mice were transplanted into wild-type mice, pups derived from the transplanted ovaries were obtained, suggesting that the ovary of UTI-deficient mice functions normally if UTI is supplied from the systemic circulation. These results demonstrate that UTI plays an important role in the formation of the stable cumulus-oocyte complex that is essential for oocyte maturation and ovulation.

Growth-stimulating effect of dienogest, a synthetic steroid, on rodent, canine, and primate mammary glands

We observed hyperplasia of the mammary gland in female beagle dogs, but not in female rats and monkeys, in 91-day toxicity studies on dienogest. In order to elucidate a possible mechanism for its development and to account for this species difference, we determined the plasma level of growth hormone (GH) in dogs, rats, and monkeys treated orally with dienogest for 91 days. As a result, dogs with mammary hyperplasia showed a prominent, dose-dependent increase in their GH level; and, contrarily, rats and monkeys without the hyperplasia of this organ failed to show any such increase. These results were supported by evidence from immunohistochemical and morphometric analysis of the pituitary gland. In addition, dienogest and medroxyprogesterone acetate (MPA) stimulated the growth of canine mammary epithelial cells in the presence of estradiol in vitro, but had no effect on rat and human mammary epithelial cells incubated under the same conditions. In conclusion, dienogest with progestational activity caused proliferation of the mammary gland in beagle dogs by increasing the secretion of GH, as do other progestational compounds. This change may be partially dependent on the direct effect of the drug.

Human natural tumor necrosis factor alpha induces multiple endocrine and hematologic disorders in rats

Slc:Wistar male rats treated with human natural tumor necrosis factor alpha (hn TNF-alpha, 3 X 10(5) Japan reference units/kg intravenously) for 3 months showed histologic vacuolation of basophils in the anterior pituitary, hyperplasia of the thyroidal follicular epithelium, and hyperplasia of the testicular interstitial cells. The vacuolated basophils were immunohistochemically shown to be thyrotrophs. In addition, there were decreases in plasma levels of triiodothyronine (T3), thyroxin (T4), and testosterone, and an increase in thyroid-stimulating hormone (TSH). The number of lymphocytes in the marginal zones of lymphoid follicles in spleen and lymph nodes and B-lymphocytes in the peripheral blood decreased. Hyperplasia of hematopoietic cells in the bone marrow and decreases in both leukocytes and erythrocytes in the peripheral blood were prominent. Hyperplasia of bile ductular epithelial cells with periportal mononuclear cell infiltration in the liver and increased cellularity in alveolar walls in the lung were also characteristic. In in vitro studies, hn TNF-alpha inhibited both proliferation and peroxidase activity of thyroid follicular epithelial cells. These findings demonstrate that hn TNF-alpha may induce histologic vacuolation of thyrotrophs by causing a decrease in plasma levels of T3 and T4; hyperplasia of the thyroid follicular epithelium, which may be attributed to the increased plasma level of TSH; hyperplasia of testicular interstitial cells, by lowering the plasma level of testosterone; hyperplasia of bile ductular epithelial cells; hyperplasia of hematopoietic cells in bone marrow; and the increase in cellularity in pulmonary alveolar walls. In addition, hn TNF-alpha may suppress the differentiation of B-lymphocytes.

Acute toxicity of an anti-Fas antibody in mice

By histopathologic examination of various organs in 3 normal strains, C3H/HeN, ICR, and DBA/1J, of mice treated intravenously once with anti-Fas antibody (Jo2), we failed to determine any target organ, except the liver, responsible for the acute lethality induced by the Fas/anti-Fas antibody interaction. However, we could show the presence of Fas-mediated apoptosis in other organs aside from the liver and normal mouse strain differences in susceptibility to anti-Fas antibody. Among these strains, C3H/HeN was the most susceptible to the antibody, followed by ICR and DBA/1J. We observed Fas-mediated apoptosis in the liver, spleen, thymus, lymph nodes, Peyer's patch, intestine, skin, coagulation glands, ovary, uterus, and vagina in all 3 strains and additionally in the epididymides and seminal vesicles in the DBA/1J strain. We also demonstrated that Fas-mediated apoptosis of small lymphocytes in the mantle zone of splenic lymphatic follicles preceded that of the hepatocytes or thymic cells. Since cellular damage was most severe in the liver among all the apoptotic organs in the 3 mouse strains, liver injury induced by anti-Fas antibody is speculated to play a significant role in the death.

Histopathological and biochemical studies on pancreatic fibrosis in WBN/Kob rats

We investigated the time-course of changes in pancreatic fibrosis accompanied with pancreatitis in WBN/Kob rats. The areas of fibrosis and fatty replacement were analysed morphometrically, and biochemical measurements of pancreatic and plasma prolyl hydroxylase and of pancreatic collagenase were assessed. Male rats showed acute pancreatitis at 2-3 months of age, lesions that later underwent a transition to widespread fibrosis. The fibrosis then decreased, and the fibrotic tissue was replaced with adipose tissue. Morphometrically, the fibrotic area reached its maximal size when the rats were 4 months old, diminishing thereafter. The fibrosis occurred mainly in the intralobular space, and was principally attributable to type-III collagen. Type-I collagen scarcely appeared throughout the experimental period. Alpha-Smooth muscle actin appeared in and around myofibroblasts that developed in an early stage and diminished later in accordance with the progressive manner of fibrosis. The plasma prolyl hydroxylase level was higher in males than in females from 4 through 10 months of age. Pancreatic collagenase activity in the males also increased during the same period. These findings suggest that pancreatic fibrosis in male WBN/Kob rats is affected by the balance between prolyl hydroxylase and collagenase.

Lipoteichoic acid induces preterm delivery in mice

The purpose of this study was to determine whether or not lipoteichoic acid (LTA) could induce preterm delivery in mice. On days 15 and 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given intraperitoneal injections of LTA (12.5-75 mg/kg, single dose or repeated doses at a 3-h interval). We examined the changes in cervix, placental trophoblasts, and plasma and amniotic fluid concentrations of interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) after dosing with LTA. In addition, the effect of LTA on the contraction of isolated uterine muscle from pregnant mice was also measured. The incidence of preterm delivery was highest (100%), when the pregnant animals were treated with 75 mg/kg LTA twice on day 15 of pregnancy or with 25 mg/kg LTA twice on day 17 of pregnancy. LTA-accelerated cervical ripening and placental abruption preceding the onset of preterm delivery, as well as increased plasma and amniotic fluid concentrations of IL-1alpha, IL-6, and TNF-alpha. Also, LTA increased contraction of uterine muscle strips. In conclusion, LTA induced preterm delivery in mice in the same manner as lipopolysaccharide (LPS), but the effective dose of LTA was larger than that of LPS.

Trophoblastic apoptosis in mice with preterm delivery and its suppression by urinary trypsin inhibitor

OBJECTIVE

To investigate histopathologic changes of the placenta in mice with preterm delivery induced by lipopolysaccharide and the effect of urinary trypsin inhibitor.

METHODS

Female C3H/HeN mice impregnated by male B6D2F1 mice were treated with lipopolysaccharide (50 micrograms/kg, intraperitoneally) or lipopolysaccharide plus urinary trypsin inhibitor (25 x 10(4) U/kg, intraperitoneally). At 3, 6, 9, and 18 hours after the second dose of lipopolysaccharide, and at delivery in the control and urinary trypsin inhibitor-treated groups, the concentrations, of interleukin-1 alpha and tumor necrosis factor-alpha were determined in serum and amniotic fluid. Subsequently, the placentas were examined. In the same manner, we examined mice treated with interleukin-1 alpha (250 micrograms/kg, subcutaneously) on day 15 of pregnancy and intact mice on days 15 and 18 of pregnancy as well as at delivery. To assess the direct action of cytokines, we cultured placental slices with tumor necrosis factor-alpha, interleukin-1 alpha, or tumor necrosis factor-alpha plus urinary trypsin inhibitor and examined them morphologically.

RESULTS

Control mice were characterized by trophoblastic apoptosis and increased serum levels of tumor necrosis factor-alpha and interleukin-1 alpha. In contrast, urinary trypsin inhibitor-treated mice showed suppression of apoptosis and lower cytokine levels. Interleukin-1 alpha induced trophoblastic apoptosis and increased the serum level of tumor necrosis factor-alpha. The in vitro study showed that tumor necrosis factor-alpha directly induced trophoblastic apoptosis in placental slices.

CONCLUSION

We demonstrated that trophoblastic apoptosis occurs in the placentas of a mouse model with preterm delivery induced by lipopolysaccharide. We postulated that apoptosis may lead to placental abruption, and its development may be prevented by treatment with urinary trypsin inhibitor.

Ability of intrauterine bacterial lipopolysaccharide to cause in situ uterine contractions in pregnant rabbits

BACKGROUND

To investigate the ability of bacterial lipopolysaccharide delivered by the intra-uterine route to cause uterine contractions in rabbits, and to assess the suppressive effect of urinary trypsin inhibitor on them.

METHODS

Both pregnant and non-pregnant rabbits were chronically implanted with a force-transducer to make it possible to record isometric uterine contractions under unanesthetized and unrestrained conditions. Lipopolysaccharide (10 micrograms/animal) was administered via a catheter to their uteri; and then, after confirmation of lipopolysaccharide-induced uterine contractions, urinary trypsin inhibitor (3,000 or 10,000 units/animal/time) or saline solution was injected through the catheter, 5 times for pregnant animals or 3 times for non-pregnant animals at 1-hour intervals in both cases. Their uterine contractions were continuously recorded for 3 to 5 hours. Effects of lipopolysaccharide (10 micrograms/ml) and urinary trypsin inhibitor (100 and 1,000 units/ml) on the contraction of isolated uteri from pregnant mice were also measured, as was their production of prostaglandin E2 and prostaglandin F2 alpha by an enzyme immunoassay method.

RESULTS

Lipopolysaccharide augmented the in situ uterine contractions in both pregnant and non-pregnant rabbits, as well as the in vitro contractions of isolated uteri from pregnant mice. Lipopolysaccharide also increased the uterine prostaglandin production. Urinary trypsin inhibitor inhibited significantly the lipopolysaccharide-induced uterine contractions and the prostaglandin production.

CONCLUSIONS

Lipopolysaccharide enhanced uterine contractions through, at least partly, a direct mechanism via uterine prostaglandin production, which action could explain the onset of preterm delivery due to intrauterine bacterial infection. As urinary trypsin inhibitor suppressed the lipopolysaccharide-induced uterine contractions, this inhibitor may be a hopeful candidate of a drug for prevention of preterm delivery.

Usefulness of a new tactile sensor for measurement of uterine cervical ripening in mice in a quantitative and noninvasive manner

OBJECTIVE

The purpose of this study was to establish a method with a new tactile sensor for determining in a quantitative and noninvasive manner the extent of uterine cervical ripening.

STUDY DESIGN

We used a newly designed tactile sensor to measure the softness of the cervix in untreated nonpregnant, pregnant, parturient, and nursing mice and then on day 15 of gestation in pregnant mice treated with dehydroepiandrosterone sulfate or Escherichia coli lipopolysaccharide. Additionally, to elucidate the correlation between the extent of cervical softness and its morphologic changes, we observed microscopically the uterine cervices.

RESULTS

The hardness of the murine cervix decreased with the progression of pregnancy and became minimal at delivery. We demonstrated for the first time with a tactile sensor for measuring hardness that dehydroepiandrosterone sulfate and lipopolysaccharide significantly decreased the stiffness of the murine cervix. These findings were supported by the morphologic observations on the cervices.

CONCLUSIONS

These results show that the tactile sensor for measuring hardness makes it possible to determine the extent of cervical ripening quantitatively rather than qualitatively. We consider that cervical ripening determined objectively in this manner is a good parameter to predict the onset of preterm delivery.

Spontaneous adrenal and hepatic myelolipomas in the common marmoset

Myelolipomas occurring simultaneously in the adrenal and liver were found in a 2.7-yr-old, bred female common marmoset (Callithrix jacchus). The animal bore single adrenal and multiple hepatic myelolipomas. The adrenal myelolipoma consisted of mature adipose cells and focal collections of normal hematopoietic elements and was unencapsulated. In the liver, the myelolipomas, which were partially encapsulated, included a large amount of hematopoietic tissue and adipose cells that resembled normal bone marrow cells in various ways. Additionally, one of the multiple nodules contained several bony spicules with osteoblasts. Furthermore, there were invasive figures of hematopoietic cells, such as myeloblasts, erythroblasts, and megakaryocytes, in the hepatic sinusoids around the lesions. Thus, this case has some unusual morphological characteristics and is the first report, to our knowledge, on multiorganic myelolipomas in common marmosets.

Successful heterotransplantation of human endometrium in SCID mice

OBJECTIVE

To establish an experimental system useful for long-term evaluation of human endometrial tissue by its heterotransplantation to SCID mice.

METHODS

Human endometrium was transplanted subcutaneously into SCID mice, nude mice, or nude mice given anti-asialo GM1 antibody, a natural killer activity suppressor. The transplant was observed by ultrasonography for up to 10 weeks and then morphologically. To assess the drug susceptibility of the transplant, danazol (10-100 mg/kg/day orally), buserelin (0.01 mg/kg/day subcutaneously), or estradiol (0.5 mg/kg/day intraperitoneally) was administered to the host mice for up to 10 weeks after the transplantation. Multiple-comparison procedures were used for statistical evaluation.

RESULTS

The heterotransplant was accepted 100% in SCID mice and natural killer activity-suppressed nude mice, but was significantly inferior (40%) in nude mice at 10 weeks after the transplantation. The transplant size was volumetrically measurable noninvasively by ultrasonography. Using this SCID mouse model, we could evaluate drug effects on the transplanted endometrium.

CONCLUSION

This system in SCID mice may be useful for evaluating drug actions on human endometrium and endometriotic tissues.